The trial of the Penn Hills man charged with killing a rabbinical student from Toronto is expected to begin today, nearly 15 years after the victim was gunned down on a quiet Squirrel Hill street for reasons that neither an arrest nor the passage of time has made clear.

The suspect, Steven M. Tielsch, 38, of Penn Hills, was arrested nearly a year ago, primarily based on statements from two informants who said Tielsch separately admitted to them that he was the person who fatally shot Neal S. Rosenblum.

Deputy District Attorney Daniel E. Fitzsimmons will be the prosecutor and James A. Wymard will provide the defense in the jury trial before Allegheny County Common Pleas Judge W. Terrence O'Brien that is expected to last more than a week.

"He is absolutely innocent of these charges and the trial will establish that," Wymard said yesterday.

At the time of Tielsch's arrest on Feb. 17, detectives said they still weren't certain of a motive in the killing. Then-city police Cmdr. Ronald Freeman, who recently retired, said at a news conference announcing the arrest that it was the gut feeling of detectives that Rosenblum was the victim of a hate crime.

The Rosenblum case, which among detectives came to be known simply and respectfully as "The Rabbi," was one of the most publicized in the city's history.

Rosenblum, 24, his wife and the couple's month-old daughter had been in town for only seven hours when he was shot five times about 9:15 p.m. on April 17, 1986, on Pittock Street near Phillips Avenue in Squirrel Hill. He was shot in the abdomen, chest, arms and leg as he walked alone back to his in-laws' Shady Avenue home following prayers at Kollel Bais Yitzchok Torah Institute Study Center on Bartlett Street.

There was speculation that the bearded and bespectacled Rosenblum, wearing traditional garb favored by some Orthodox Jews -- a long black raincoat, a black suit, white shirt, black yarmulke and black fedora -- had been gunned down solely because of his religion. Detectives wondered whether heightened Israeli-Arab tensions in the world at the time played some part in the slaying.

Before being taken to UPMC Presbyterian, where he died four hours after the shooting, Rosenblum told Pittsburgh police Officer Al Stegena, who is now a detective, that a white male passenger in a black sports car with pop-up headlights asked him for directions and then opened fire as he approached the car. A white man was driving, he added.

Stegena asked Rosenblum if the car was like a Corvette and Rosenblum said it was.

At a preliminary hearing in March, a former cellmate of Tielsch's testified that Tielsch told him in their cell in the Allegheny County Jail Annex that he was the shooter in the Rosenblum killing and that a man named "Kevin" was driving Tielsch's black Corvette because Tielsch's license was suspended at the time. Homicide detectives asked media representatives covering the hearing not to photograph the informant or report his name because of fears for his safety.

The witness said Tielsch, who was charged with federal narcotics crimes, made anti-Semitic remarks about Rosenblum and Assistant U.S. Attorney Bruce J. Teitelbaum and said he would like to kill him. Moreover, Tielsch often drew a swastika on his forehead, the witness said.

The witness said he told his attorney of Tielsch's confession about the shooting and the anti-Semitic comments because he wanted to get away from him.

The witness said he is Jewish, but Tielsch didn't know it. He testified that his attorney said he should tell police what he had heard and he did so in April 1988, two years after the killing.

Reacting to that information, detectives learned that the "Kevin" who Tielsch said was driving was another Penn Hills man, Kevin Ohm, 26.

Ohm told detectives that on the night of Rosenblum's slaying, he and Tielsch free-based, or smoked, cocaine and also took pills. He recalled driving Tielsch's black Corvette with Tielsch as a passenger. The men drove around, shooting a gun at street signs. But because of the drugs, Ohm said, he couldn't recall whether he was with Tielsch when Rosenblum was shot.

Ohm was killed in a traffic accident in Penn Hills in August 1991. Tielsch was driving that car -- a vehicle other than his Corvette -- and was convicted of vehicular homicide.

Detectives weren't successful in finding corroboration for the first informant's story until last spring, when another man told them Tielsch had confessed the same information to him, leading to the arrest.

Tielsch's Corvette could not be found. There was no record of Tielsch renewing his registration or selling or junking it. Detectives speculated he had it "chopped," taken apart and sold for parts, or destroyed.